1. Field of the Invention
The present invention relates to an image forming apparatus including multiple optical heads and an image displacement correction method therefor.
2. Description of the Related Art
Japanese Patent Application Publication No. 2011-194684 discloses an electrophotographic image forming apparatus including first and second print heads arranged so that their end portions overlap each other in a main scanning direction, and being capable of printing an image on a wide recording medium. This image forming apparatus calculates a displacement amount between the first and second print heads based on density of a pattern image formed on a photosensitive drum and predetermined reference density data, and corrects displacement between the first and second print heads based on the calculated displacement amount.
Japanese Patent Application Publication No. 2001-134041 discloses an electrophotographic image forming apparatus including multiple printing units along a conveyance path for a recording medium, and being capable of color printing. This image forming apparatus detects color displacement amounts in a conveyance direction of the recording medium from detection pattern images printed by the multiple printing units, and corrects printing positions of the printing units in the conveyance direction of the recording medium based on the detected color displacement amounts.
It is desirable that image displacement be corrected in a short time.